Generally, a magnetic sensor may have two magnetism detection elements. In a patent document, Japanese Patent No. 5688691 B (patent document 1), detection values from the two magnetism detection elements are compared with each other for abnormality determination, and when the detection value is determined as abnormal, a voltage signal indicative of an abnormal range that is outside of a normal range is outputted to an Electronic Control Unit (ECU).
In the patent document 1, only one kind of abnormality is output as an abnormality determination signal, based on a comparison between the two detection values. However, through an output of the abnormality determination signal as the voltage signal indicative of the abnormal range that is outside of the normal range by an analog communication, information other than abnormality information that indicates whether a magnetic sensor is abnormal cannot be output and be notified to the ECU.